US8265545B2 - Wireless environment method and apparatus - Google Patents

Abstract

A method and apparatus are provided for a first controlled device, such as a wireless local transmitter that accepts a plurality of digital audio signals and corresponding program information signals converted from a controlled source, such as the encoded digital data provided by a digital data signal source, typically a community antenna television (CATV) cable or direct broadcast satellite, then modulates said digital audio and corresponding program information signals on different carrier frequencies and transmits the modulated signals to a plurality of second controlled devices, such as remote digital receiver/tuners that demodulate said signals to output music in stereophonic sound and display the corresponding program information by means of an alphanumeric display. The first and second controlled devices contain microprocessor systems for communicating, controlling, storing, processing, and display of digital data within the operation of the respective system. A high speed, error free digital signal protocol is utilized for transmitting digital audio and corresponding program information signals to and from the digital receiver/tuner. The digital data transmitter and digital receiver/tuners utilize the 44.1 kilohertz (kHz) Compact Disc (CD) clock signal embedded in digital audio signals provided by an established delivery system to derive clocking signals for reception and processing of digital audio signals and for implementing the display information communications protocol.

Description

CROSS REFERENCE TO RELATED DOCUMENTS

This application is a continuation of U.S. patent application Ser. No. 12/363,593 filed Jan. 30, 2009 now U.S. Pat. No. 7,962,090 entitled “Method And Apparatus for Satellite Digital Audio,” which is a continuation of Ser. No. 10/878,731, now U.S. Pat. No. 7,502,604 filed Jun. 28, 2004 entitled “Wireless Environment Method And Apparatus,” which is a continuation of Ser. No. 09/798,331, now U.S. Pat. No. 6,757,913 filed Mar. 1, 2001 entitled “Wireless Music & Data Transceiver System” which is a continuation of Ser. No. 08/886,951, filed Jul. 2, 1997, now U.S. Pat. No. 6,212,359 entitled “Transceiver System For Digital Music” which claims benefit of provisional application Ser. No. 60/021,721, filed Jul. 15, 1996 entitled “Wireless Stereophonic Transmitter And Receiver/Tuner System,” said applications are incorporated herein by reference in their entirety and made a part hereof.

BACKGROUND OF THE INVENTION

The cable television industry developed and refined a process of audio signal compression in the mid-1980's. The process allows for extra space on coaxial cable wire by electronically compressing audio signals between the video bandwidths that carry the television signal. By the late 1980's, audio signal compression technology spawned an industry that has come to be known as “digital music.” Digital music is developed by cable conglomerates and is sold to subscribers along with their cable television service. This audio music signal is produced at one location by using multiple compact disc players playing continuous music in a variety of formats then sent via satellite to local cable companies. The audio music service is also currently available as a premium service via direct broadcast satellite (DBS), but other methods, such as fiber optics, telephone systems, microwaves, or Internet enabled technologies for example, could also deliver the signal.

The local multisystem operators (cable and DBS companies sell the service to subscribers who pay a monthly fee for a headunit or “tuner”) compress the signal, then sell the service to subscribers. This unit decompresses the audio signal, then converts it into an analog signal which can be heard through the television audio source or be used in conjunction with a home stereo component system. The user can choose from multiple channels using an infrared remote control or with tuner controls located on the headunit. With the Digital Music Express product, including song title, artist, album, and record label can be viewed on an LCD (liquid crystal display) window located on the infrared remote that operates the tuner as described in U.S. Pat. No. 5,445,570. This system to Cook correctly postulates the value of listener access to program information; specifically, that there is a strong possibility for loss of revenue due to subscription cancellation if a subscriber has no method of knowing the program information that corresponds to the song they are listening to. Furthermore, Cook explains that to the music industry, identification of the recording label and the musical selection is critical to the sale of recordings.

Digital music has not developed as proponents predicted. Since its national introduction in the early 1990's, sales penetration has been an unimpressive 1.5-2.5 percent among the multisystem operators offering the service. Research has revealed that digital audio is a unique product, but with very little recognition among subscribers. And, despite a myriad of marketing schemes, neither operators nor the two major cable audio producers can claim to have found a definitive solution to drive sales.

The problem with the current product is that it is not versatile. It can only interface with an existing stereo component or loudspeaker system. Subscribers are also bound to a single choice of music located in the room where the converter/tuner box is located. Because the cable music service is not available in the convenience of technology such as a portable disc player, a portable bookshelf stereo, a portable radio/tape player, or more popular mediums for listening to electronic music, it will never be as attractive as it could be to the consumers who would most appreciate its advantages.

As mentioned above, presently, the only means to access the audio signal provided by the cable music services is through use of a stationary output device, such as a rack stereo system with auxiliary inputs for the digital music tuner. U.S. Pat. No. 5,282,028 entitled “Remote Control for Digital Music Terminal with Synchronized Communications” and U.S. Pat. No. 5,455,570 entitled “Methods And Apparatus For Communication Program Data Signals Via A Remote Control Unit” incorporated herein by reference, disclose systems wherein an infrared remote controls and communicates with a digital music tuner. To use the tuner, changing channels or viewing program information, the listener must be close enough in proximity to the tuner to use the infrared remote; this can be frustrating if a variety of formats or program information is of interest to a listener who within sound range but out of the reception range of the remote control. Also, only one music channel can be accessed at a time, limiting all listeners to a single music format. Additionally, if currently available tuners were combined with multiple output devices in a single structure, competing tastes in music preference and volume would contribute to unnecessary costs and unwanted noise pollution. Prior art has recognized the value in wireless stereophonic signals. U.S. Pat. No. 4,829,570 to Borchardt describes a F.M. (frequency modulation) signal transmitter/receiver system which is then outputted to loudspeakers. The Borchardt system converts an audio signal into a F.M. signal, transmits the F.M. signal over A.C. power lines, and reconverts the F.M. signal into an audio signal which is outputted at the source. The problem with such a device is that it has limited function. Only one signal is sent from the transmitter to the receiver. The receiver must be a stationary device with auxiliary inputs to accommodate the transmitted signal. And, the listener must return to the signal source to change the input. RF Link markets a similar product, Wavecom Jr., that transmits audio and video signals on a gigahertz frequency, but is subject to the same limitations of the Borchardt system. U.S. Pat. No. 5,491,839 entitled “System For Short Range Transmission Of A Plurality Of Signals Simultaneously Over The Air Using High Frequency Carriers” to Schotz discloses a system for transmitting analog or digital signals. Schotz suggests that three electrical input signals be comprised of conventional audio sources, such as a compact disk, or tape deck, but not digital audio or program information to a plurality of receiver/tuners that allow a listener to interact with the music service.

In general, such prior art systems are limited in range, signal strength, variety of channels, program information available, and overall accessibility and ease of use. Consequently, a requirement exists for a local transmitter and digital receiver/tuner system that communicates under a control to provide reception of the digital audio music and display of corresponding program information which can be located at the convenience and discretion of multiple listeners.

OBJECTS OF THE INVENTION

It is, therefore, the object of the present to provide a wireless local transmitter and digital receiver/tuner system for transmitting and receiving digital audio and corresponding program information that will overcome the limitations of conventional methods of transmitting and receiving digital audio and corresponding program information.

It is another object of this invention to provide a transmitter that can receive digital audio and program information input from a plurality of sources and can simultaneously broadcast a plurality of digital audio and program information signals over a limited range.

It is still another object of this invention to provide a transmitter that can simultaneously broadcast a plurality of digital audio and program information signals via a combined digital signal.

It is an additional object of this invention to provide receivers that can simultaneously receive a plurality of combined digital audio and program information signals broadcast by the transmitter, and can select one of the digital audio signals and display corresponding program information signals broadcast from the transmitter.

It is still an additional object of the present invention to utilize an existing clock oscillator having a predefined frequency within a first and second device to enable the transmission and reception of digital audio and program information between the two devices using the predefined frequency to generate a wireless digital carrier signal.

It is a further object of the present invention to provide a two-way communications link between a plurality of receiver/tuners and the first controllable device which allows the listener to interact with the service with, for example, viewing program information, participate in surveys of music preferences, or storing program information for future use, or purchase of music via electronic accounts.

It is yet a further object of the present invention to provide an error detecting or an error checking process for receiving an entire, error-free message from a predetermined number of transmissions between a controllable device and a receiver/tuner of a message defined by a predetermined number of data fields.

BRIEF DESCRIPTION OF THE DRAWINGS

The following detailed description, given by way of example, and not intended to limit the present invention solely to the embodiments shown and described herein, will best be understood in conjunction with the accompanying drawings in which:

FIG. 1: is a schematic representation of the overall transmitter and receiver/tuner system configured in accordance with this invention;

FIG. 2: is a block diagram of the transmitter of the system;

FIG. 2a: is a block diagram of the transmitter synchronizing circuit.

FIG. 3: is an example of a top plan view of one variation of the receiver/tuner units constructed in accordance with the preferred embodiments of the present invention.

FIG. 4: is a block diagram of the receiver/tuner of the system.

SUMMARY OF THE INVENTION

The problems of providing digital audio and display of corresponding program information associated with a digital music service are solved by the principles of the present invention. The present invention ensures that a listener will continue to enjoy the advantages of digital audio, while also enabling portable reception of the service within a localized setting. Also, the invention provides a means for the user to participate in music surveys, store desired program information, and purchase of music via electronic accounts, by combing a wireless receiver/tuner unit that communicates with and controls a first controlled device, such as a digital audio and program information transmitter unit.

A system constructed in accordance with the present invention is comprised of two primary components, a transmitter and at least one receiver/tuner. The transmitter serves as an addressable controller that includes input means, encoders/decoders associated with the system, demultiplexer, service codes, converter means, carrier signal producing means, combining means, and antenna means. The converter contains a digital to RF (radio frequency) converter module, demodulator, addressable control interface logic, subscriber interface logic, and decryptor. The input means is arranged for receiving a multiplexed serial digital data audio/program information stream that includes a plurality of the digital audio, program information, and national subscriber information signals from said multiplexed serial stream.

The carrier signal producing means is arranged for providing at least a first group of carrier signals, with that group comprising a set of different carrier signals. Each of the carrier signals of the group is preselected and is different from the others of the group, and is at a frequency of at least 900 mHz.

The modulating means is coupled to the input means for modulating the carrier signals of the first group with respective ones of the plurality of input signals to produce a plurality of modulated carrier signals. The serial stream is modulated using multiphase or multilevel amplitude or frequency modulation of the carrier in the F.M. broadcast band. The means for combining is coupled to the modulating means for combing the modulated carrier signals into a combined signal and for providing the combined signal to the antenna means. The antenna means radiates the combined signal over the air.

The receiver/tuner is a device consisting of subcomponents including a microprocessor, addressable controller interface logic, RF to digital converter, signal amplifier, tuning synthesizer, subscriber interface logic, LCD display, demodulator, local oscillator, keypad interface, and output amplifier. The receiver means is arranged for receiving the combined signal and for demodulating a selected one of the carrier signals in the group so that the input signal is extracted therefrom for reproduction by transducer means coupled to the receiver means.

The transmitter means provides plural groups of different carrier signals comprising plural carrier signals which are different from the other signals in that group and from the carrier signals in the other groups and are of a frequency of at least 900 mHz. First user-selectable means are provided in the transmitter means and in the receiver means to select a desired group of carrier frequencies for system operation. Second user-selectable means are provided in the receiver means to enable the user to select a desired carrier frequency of the selected group to be demodulated so that they can hear the digital audio and view the program information signal extracted therefrom by such demodulation. The multiple groups of carrier frequencies available enables a selection of a group of carrier frequencies which are different from those which may be used by another like system operation within the operating range of the system to ensure that there will be no interference by that other system.

DETAILED DESCRIPTION OF THE INVENTION

With reference first toFIG. 1, a system is illustrated therein for local wireless transmission and reception of digital audio and program information. Adelivery system10, such as coaxial cable, satellite, the Internet, microwave, and etc., outputs a serial digital audio/program information stream22 that contains digital audio, program information, and national subscriber information. Thetransmitter100, more fully described with respect ofFIGS. 2-2a, receives the said serialdigital data stream22 and demultiplexes, decrypts, and decodes the digital audio and program information signal. The digital audio signal and program information are converted to a digital RF carrier frequencies and broadcasted to a plurality of second devices, preferably at least one receiver/tuner unit200, more fully described with respect ofFIGS. 3-4, that outputs the selected audio electronically and displays the corresponding program information of the audio track currently listened to by the subscriber.

Digital Music Transmitter

FIG. 2 is a block diagram of the preferred digital music transmitter (DMT)100. Referring toFIGS. 1-2, the serialdigital data stream22 is passed via an established system ofdigital data distribution10, for example, multisystem operators coaxial cable or direct broadcast satellite, and is received by thetransmitter input terminal105. Thetransmitter input terminal105 preferably includes phase-lock loop (PLL) circuitry. The signal is amplified by anamplifier110 and filtered by aSAW filter115 before being demodulated by ademodulator120. Thedemodulator120 converts the selected digital frequency to demodulation intermediate frequency (IF). The output of thedemodulator120 is quadrature partial response (QpR) demodulated to produce a 5.6 Mbps data stream containing 150 stereo pairs of digital audio data to an applications specific integrated circuit (ASIC)130. Thedemodulator120 provides data to a dataclock recovery PLL125. The dataclock recovery PLL125 contains a 33.8688 mHz crystal122 (about 33.9 mHz) for timing purposes.

TheASIC130 provides demultiplexing, decrypting, and decoding operations upon the 5.6 Mbps data stream input by thedemodulator120 to themicroprocessor140. TheASIC130 separates the 5.6 Mbps data stream to a select one of 150 stereo pairs of digital audio signals. The selected stereo pair is decrypted and separated to provide digital audio signal and a program information signal. The digital audio signal is then decoded according to a variety of known techniques. TheASIC130 inputs the digital audio signals, provided at a sampling rate of 44.1 kilohertz (KHz), to adigital RF converter150. The audio signals are provided to a F.M. stereo encoder andloudness processor152, and then to F.M.band exciter154. The output of theexciter154 is amplified by ahigh power amplifier156 and broadcast over the airwaves by anantenna160 as digital F.M. in the F.M. broadcast for reception by a digital F.M.receiver201, such as disclosed inFIG. 3

Areceiver170 for a second controllable device, such as a digital receiver/tuner (DRT)200, coupled to themicroprocessor140 receives instruction or control signals transmitted by theDRT200 to initiate the remote control of selected functions of thetransmitter100. A clock signal generated internal to theASIC130 is utilized as a carrier signal to switch the output of theDRT200 ON or OFF at a frequency of 44.1 KHz. The 44.1 KHz clock from anASIC Clock generator130amay be utilized to generate a carrier signal for RF signals sent by theDRT transmitter160. The ASIC Clock signal provided by theASIC clock130ais derived from the about 33.9 mHz signal provided to theASIC130 by thedata clock PLL125. TheDRT200 operates to control selected function of the transmitter as well as the program information transmitted by theDRT transmitter160 associated with theDMT100.

The ASIC Clock signal provided by theASIC clock130 is derived from the about 33.9 mHz signal provided to theASIC150 by thedata clock PLL125. Specifically, the ASIC Clock signal is derived by dividing the 33.9 mHz signal by three (3) to provide a second clock signal having a frequency of 11.3 mHz, and by then dividing the 11.3 mHz signal to the preferred fixed first frequency for the 44.1 kHz ASIC Clock signal. The 11.3 mHz clock signal is utilized as a clock signal selected operations conducted by theASIC130. TheASIC130 contains a synchronizingcircuit132 which is utilized to provide clock synchronized program information signals to theDRT200. The synchronizingcircuit132 operated to provide two separate timing alignment functions. First, the synchronizingcircuit132 aligns the program information signal provided by the microprocessor to the 11.3 mHz clock signal. Second, the synchronizingcircuit132 aligns the 44.1 KHz ASIC Clock signal to the 11.3 mHz clock signal.

Referring toFIGS. 2-2a, the synchronizingcircuit132 includes afirst synchronizing element133, an,edge detector134, and secondsynchronized element135, andgate136. Themicroprocessor140 provides program information signals in the form of a serial data signal formatted in the appropriate display information protocol to thefirst synchronizing element133. Themicroprocessor140 outputs the program information signals to thefirst synchronizing element133 at a predefined data rate, preferably 4900 baud. In addition, the 11.3 mHz clock signal is provided as another input to the firstsynchronized element133. Thefirst synchronizing element133 aligns the rising edge of the program information signals to the 11.3 mHz clock signal to provide an output signal synchronized with the 11.3 mHz clock. Thesecond synchronizing element135 accepts the synchronized output signal of thefirst synchronizing element133 and produces a gate signal when the output signal of theedge detector134 enables thesecond synchronizing element135. The gate signal produced by thesecond synchronizing element135 and the ASIC clock signal of 44.1 kHz are provided as inputs to an ANDgate136. Accordingly, the integral number of cycles of the ASIC clock signal output by the ANDgate136 is effectively determined by the pulse width or pulse duration of the gate signal output by thesecond synchronizing element135.

The output of theASIC130 is a carrier-modulated program information signal, produced by an on/off keying technique, and is provided from the synchronizingcircuit130 online137 to theDRT transmitter160. The carrier-modulated program information signal, when formatted with appropriate start bits, stop bits, and other formatting information described below, comprises a display information signal that is ultimately display as alphanumeric characters on the display of theDRT200. TheDRT transmitter160 is responsive to the carrier-modulated program information signal provided online137. Themicroprocessor140 initiates a transmission of a program information signal by theDMT100. In response to the initiation of a transmission, theASIC130 outputs the synchronized program information signal at the rate defined by the first frequency (44.1 KHz) to theDRT transmitter160.

TheDRT receiver170 includes ademodulator172 andRF diode174. TheRE diode174 is located between an input of thedemodulator172 and the ground. When theRF diode174 detects a command signal from theDRT200. TheRF diode174 outputs a detected signal to thedemodulator172. Thedemodulator172 demodulates and filters the detected RF signal and provides an output voltage signal to the receiver input terminal of themicroprocessor140 online173. Thedemodulator172 provided the specific functions preamplification, bandpass filtering, and detection of the detected RF signal provided by theRF diode174.

Digital Receiver/Tuner

FIG. 4 is a block diagram of the preferred digital receiver/tuner (DRT)unit200. The preferred DRT units, not limited to the embodiments inFIG. 3, include a display for the control of the digital music transmitter (DMT)100. The top surface of theDRT200 includes an alphanumeric character display and a matrix of contact switches forming a keypad. Each contact switch of the keypad is covered by a push button or key that includes a label which defines the function or instruction initiated when the user presses the push button. In addition, selected areas of the tip surface of the DRT unit include labels or other indicia that further designate the function or instruction associated with the key or push button. The user can control the functions of theDMT100 in a manner similar to the use of currently popular wireless transmitter/receiver units that control the functions of consumer products, such as cordless telephones or local audio signal transmitter.

Specifically, theDMT100 remains in a dormant mode with a transmitted passive signal that responds to a selected command function from theDRT unit200. The user can initiate or terminate transmission of the digital audio and program information from theDMT100 by pressing a selected key. Each of the buttons or key of the keypad is labeled to indicate the function associated with the key.

For example, by pressing any key or a set of keys labeled with Arabic numerals 0-9, a user can select one of the available digital audio and program information channels transmitted by theDMT100 for the listening pleasure of the subscriber. The keys labeled TUNE (up arrow) and TUNE (down arrow) may be used by the listener to increment or decrement the digital audio and program information channels transmitted by theDMT100. In a similar fashion, a volume up (VOL up arrow) and a volume down (VOL down arrow) keys can be utilized to control the volume level provided by theDMT100. An ON/OFF key with a power indicator light may be utilized by the listener to either power on or off theDRT200 andDMT100 signal transmission. Also, a MUTE key is useful for eliminating the audible portion of the program provided by theDMT100. Those persons skilled in the art will appreciate that such control functions are similar to the control function provided by other wireless remote controls for consumer products.

Other control function related to the control of theDMT100 by theDRT unit200 include control functions associated with the keys ENTER/NEXT. PRESET and MODE. By pressing the ENTER/NEXT key, the user initiates a command function that may be associated with the various functions of theDRT unit200. The PRESET key permits the user to store a favorite digital audio channel for future operations by theDRT unit200. The MODE function changes the message field on the LCD viewscreen according to selected function by the user, for example viewing or storing program information for a current music selection, participating in music surveys, or purchase of music via electronic account.

The listener can also review the program information associated with a current program by inputting an information request for transmission to theDMT100. By pressing the VIEW key, the user initiates the transmission of an information request by theDRT unit200 to theDMT100. The DMT processes the information request and initiates a search for program information associated with the current program. If the program information is not found by the DMT within a predetermined timer period, typically about five seconds, theDMT100 will respond to the transmitted information request by transmitting an error message to theDRT unit200. If the search by theDMT100 is successful, theDMT100 will respond to the transmitted information request by transmitting the program information to theDRT unit200. With respect to digital audio signals, a typical program message includes information concerning the composer, the track title, the artist, the album associated with the track title, and custom information concerning the current performance.

Referring toFIG. 4, thepreferred DRT unit200 includes aprocessor240, preferably a microcomputer or microcontroller, having on-board mask programmed memory, such as a read only memory (ROM)240a. The memory205acomprises plurality of memory locations for storing parameters associated with different control signal protocols (in particular, for storing a plurality of parameters associated with different control protocols for different controllable devices). Thepreferred DRT unit200 further includes aRF receiver201,demodulator218, an applications specificintegrated circuit ASIC230, digital/audio converter270,transmitter260, a dataclock recovery PLL225,front panel interface250,stereo output amplifier280.

The output of thedemodulator218 is quadrature partial response (QpR) demodulated to produce a 5.6 Mbps data stream containing 150 stereo pair of digital audio data to theASIC230. The demodulator provides data to a dataclock recovery PLL225. The dataclock recovery PLL225 contains a 33.8688 mHz crystal122 (about 33.9 mHz) for timing purposes. In the preferred embodiment, theDMT100 control signal protocols are stored in theROM240a. The control protocol includes the properly formatted codes associated with control functions for theDMT100.

TheASIC230 provides demultiplexing, decrypting, and decoding operations upon the 5.6 Mbps data stream input by thedemodulator218 to themicroprocessor170. TheASIC230 separates the 5.6 Mbps data stream to a select one of 150 stereo pairs of digital audio signals. The selected stereo pair is decrypted and separated to provide a program information signal and a digital audio signal. The digital audio signal is then decoded according to a variety of known techniques. TheASIC230 inputs the digital audio and program information signals, provided at a sampling rate of 44.1 kHz, to a digital/audio converter270,transmitter control260, andmicroprocessor memory240a. The demultiplexed control and channel data separated out from the data steam by theASIC230 are provided to amicroprocessor240 which controls the overall operation of theDRT unit200.

A clock signal generated internal to theASIC230 is utilized as a carrier signal to switch the output of theDRT200 ON or OFF at a frequency of 44.1 KHz. The 44.1 KHz clock from anASIC Clock generator230amay be utilized to generate a carrier signal for RF signals sent by theDRT transmitter160. The ASIC Clock signal provided by theASIC clock230ais derived from the about 33.9 mHz signal provided to theASIC230 by thedata clock PLL225. TheDRT200 operates to control selected functions of theDMT100 as well as the program information transmitted by theDRT transmitter260 associated with theDMT100. Referring toFIG. 2a, the ASIC Clock signal provided by theASIC clock230ais similar in function and purpose to that of theaforementioned ASIC clock130a. As result, the 11.3 mHz clock signal is utilized as a clock signal selected operations conducted by theASIC230.

Referring again to FIG.4., for a first operation mode, digital audio and program information carrier signals are received by thereceiver antenna201 from theDMT transmitter160. The received signal is provided to a double tuned tracking filter (DTTF) with PLL circuitry, from there to anamplifier203, on to a single tuned tracking filter (STTF)205, amixer207, andSAW filter209, and into ademodulator218, according to known techniques. The channel selection process is under control of atuning synthesizer220, integratingamplifier217,STTF215, andamplifier212, interconnected as shown and impressing an appropriate signal on aline211 to theDTTF201,STTF205, andoscillator210 to effect channel selection, according to known techniques. The program information signal from theASIC230 is sent to themicroprocessor240 where it may be displayed on thefront panel interface250. TheASIC230 also sends the program information signal to thetransmitter interface255 andtransmitter control260 for transmission to theDMT100. Channel selection is provided by the infrared receiver and/orfront panel interface250, which information is passed on by themicroprocessor240 to thetuning synthesizer220.

TheASIC230 inputs the digital audio and program information signals, provided at a sampling rate of 44.1 kHz to a digital/audio converter270. The output of the D/A270 device is provided as a data stream over a bus to alogic circuit274 with separates the dates stream into control bits and channel indication (tag bits) and encrypted digital audio bits (demultiplexing functions) and decrypts the digitized audio data into a suitable form for aDolby decoder278. The audio data is decrypted into three serial streams per audio channel consisting of basic delta modulation parameters for “left” and “right” channels. The output of theDolby decoder278 is provided as “left” and “right” audio channels to astereo amplifier280, and to stereo outputs for use with standard audio components.

From the foregoing description of the preferred embodiment, it will be appreciated that the present invention overcomes the disadvantages of the prior art and achieves the objects and advantages of the invention recited above. Accordingly, the invention improves existing methods of providing digital music by making the service more convenient and accessible to subscribers through wireless transmission of music to remotely located devices. Greater recognition among subscribers is gained by similarities of the preferred embodiments to more popular consumer electronic music devices. And, digital music is made more versatile with improved methods of subscriber interaction with the service. The above description of the invention is intended to be illustrative and not limiting. Various changes or modifications in the embodiments described may occur to those skilled in the art and these can be made without departing from the spirit or the scope of the invention.

Claims (20)

1. A wireless digital audio player for operation by a user, comprising:

a user interface for the user to select a digital audio program from a plurality of digital audio programs;

a tuner to tune to a radio frequency signal associated with the selected digital audio program;

a demodulator to receive from the tuner a radio frequency signal and to demodulate the radio frequency signal, wherein the radio frequency signal carries digital audio data and program information corresponding to the selected digital audio program;

a processor coupled to the user interface for separating the program information from the digital audio data; and

a digital to analog converter to convert the audio data corresponding to the selected digital audio program into an analog signal for playback by the user.

2. The wireless digital audio player ofclaim 1, wherein the user interface includes a switch for user activation of a control signal to request the transmission of digital audio data.

3. The wireless digital audio player ofclaim 2, further comprising a transmitter coupled to the user interface to transmit the control signal.

4. The wireless digital audio player ofclaim 1, wherein the user interface includes a key for transmission of a control signal for the purchase of the selected digital audio program.

5. The wireless digital audio player ofclaim 1, wherein the user interface includes a key for purchasing music using information from an account of the user.

6. The wireless digital audio player ofclaim 1, wherein the user interface includes a keypad for selecting a digital audio program.

7. The wireless digital audio player ofclaim 1, wherein the user interface includes a keypad for responding to a music survey.

8. The wireless digital audio player ofclaim 1, wherein the received radio frequency signal carries music survey data.

9. A wireless digital audio player for operation by a user, comprising:

a user interface for the user to select a digital audio program from a plurality of digital audio programs;

a tuner to tune to a radio frequency signal associated with the selected digital audio program;

a demodulator to receive from the tuner a radio frequency signal and to demodulate the radio frequency signal, wherein the radio frequency signal carries digital audio data and program information corresponding to the selected digital audio, program; and

a processor coupled to the user interface for separating the program information from the digital audio data;

wherein the user interface includes a switch for user activation of a control signal to request the transmission of digital audio data.

10. The wireless digital audio player ofclaim 9, further comprising a transmitter coupled to the user interface to transmit the control signal.

11. The wireless digital audio player ofclaim 9, wherein the user interface includes a key for transmission of a control signal for the purchase of the selected digital audio program.

12. The wireless digital audio player ofclaim 9, wherein the user interface includes a key for purchasing music using information from an account of the user.

13. The wireless digital audio player ofclaim 9, wherein the user interface includes a keypad for selecting a digital audio program.

14. The wireless digital audio player ofclaim 9, wherein the user interface includes a keypad for responding .to a music survey.

15. The wireless digital audio player ofclaim 9, wherein the received radio frequency signal carries music survey data.

16. A wireless digital audio player for operation by a user, comprising:

a user interface for the user to select a digital audio program from a plurality of digital audio programs;

a tuner to tune to a radio frequency signal associated with the selected digital audio program;

a demodulator to receive from the tuner a radio frequency signal and to demodulate the radio frequency signal, wherein the radio frequency signal carries digital audio data and program information corresponding to the selected digital audio program; and

a processor coupled to the user interface for separating the program information from the digital audio data;

wherein the user interface includes a key for transmission of a control signal for the purchase of the selected digital audio program.

17. The wireless digital audio player ofclaim 16, wherein the user interface includes a key for purchasing music using information from an account of the user.

18. The wireless digital audio player ofclaim 16, wherein the user interface includes a keypad for selecting a digital audio program.

19. The wireless digital audio player ofclaim 16, wherein the user interface includes a keypad for responding to a music survey.

20. The wireless digital audio player ofclaim 16, wherein the received radio frequency signal carries music survey data.

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